Plot hole: When Jubilee and Iceman are tied up, Jubilee has metal "mittens" over her hands that prevent her from using her powers to escape, but Iceman notes that they failed to learn about his powers and uses his ice powers to break free from his ropes. Iceman was in his ice form when X-Factor attacked him and Jubilee, and they also know that he previously attacked their compound, so they should have known that he had those abilities. (00:13:40)
Plot hole: This episode showed that Beast was an original member of the X-Men and also depicted the original X-Men battling Magneto. However, when Magneto attempted to break Beast out of jail in the season 1 episode "Enter Magneto", Beast said to him "I don't believe we've met. Magneto I presume."
Answer: Chris Potter, the original Gambit voice actor, did indeed quit the role in the 4th season. His last episode was The Phalanx Covenant Part 1 so it seems reasonable that Fox would limit the use of the character even though it was recast. It doesn't appear that Potter left the role due to animosity, he stated in an interview that he wished to play Gambit in the first live action X-Men film.
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